Electric condenser



Dec. 29 1925 J. F. LINDBERG ELECTRIC. coNDENsER l Original Filed April .7 1922 Patented Dec. 29, 1925.

UNITED STATES PATENT OFFICE.

JOHN F. LINDBERG, OF CHICAGO, ILLINOIS, ASSIGNOR TO RELIANCE DIE AND STAMP- ING COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

ELECTRIC CONDENSER.

ze, i924.

To, all whom it may concer/n: l

Be it known that I, JOHN F. LINDBERG, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Electric Condensers, of which the following is a full, clear, concise, and exact description.

My invention relates to electric condensers and to electric resistances which are well adapted for establishing restricted leakage between the sides of condensers, though the invention is not to be thus restricted. The invention also resides in combining a condenser with any suitable resistance in a manner to permit relative movement between the sides of the condenser without disturbing the adjustment of the leakage that is effected by the resistance.

The condenser of my invention includes attened coiled sheets of dielectric material and sheet metal, the latter surrounding the former and constituting one side of the condenser, and a flat sheet of metal constituting the remaining side of the condenser and located within the bore of the coiled dielectric and movable longitudinally thereof to adjust the capacity of the condensen The resistance of my invention includes two terminals and an element of insulating material assembled with said terminals and capable of receiving markings of a writing instrument, there being two thin spaced apart layers of current conducting material upon said element of insulating material individual to and respectively contacting with said terminals and projecting beyond the same to be capable of receiving and merging with a marking employed as resistance to unite said terminals.

In the preferred embodiment of the invention the two thin spaced apart layers of current conducting material are formed by broad lines of india ink. These resistance terminals may be easily and suitably connected by means of lead pencil lines drawn between them of a breadth or number to secure the desired resistance adjustment. The pencil lines readily merge at their ends with the broad ink lines. Hitherto ithas been endeavored to join metallic resistance terminals by means of lead pencil lines but it has been found that the ends of the lines do not contact as they should with such terminals.

Divided and this application filed January I will explain my invention more fully by reference to the accompanying drawing in which Fig. l is a perspective view illustrating an electric condenser and a resistance del vice associated therewith in accordance with the preferred embodiment of the invention; Fig. 2 is a sectional view on line 2 2 of Fig. l; Fig. 3 is a sectional view on line 3 3 of Fig. 1; Fig. i is a perspective view illustrating the component parts of the structure of Fig. l in separated relation; and Fig. 5 is a circuit diagram illust-rating the relation of the resistance to the condenser.

Like parts are indicated by similar characters of reference throughoutt-he different figures.

The condenser side l is `in the form 0f a metal sheet that is shaped into a flattened coil, one end ofthe sheet having a flap portion 2 which completes the formation of this condenser side into an envelope. A dielectric 3, preferably a thin sheet of mica, is also formed into a flattened coil and is enclosed by the condenser side 1. The sheets l and 3 are desirably placed together to be coiled and flattened in one operation. The remaining condenser side 4, formed o-f a sheet or ribbon of metal, is surrounded by the flattened dielectric coil 3 and is movable back and forth in order that the capacity of the condenser maybe adjusted. For the sake of convenience, the projecting end of the condenser side 4 is bent at right angles and curled to constitute a handle 5. The condenser side j l and the dielectric 3 are formed with holes 6 through which mounting screws 7 may be passed to secure the con denser to any suitable form of support such as the board 8. I connect a resistance between the sides of the condenser in such a manner that the capacity of the condenser may be varied without disturbing any resistance adjustment that has been effected. To this end the resistance is mechanically assembled with one condenser side in order that the resistance terminal which is connected with this condenser side may be normally fixed with respect thereto. The resistance terminal of the other condenser side has sliding or other changeable engagement therewith in order that the condenser capaci ty may be adjusted without disturbing the resistance adjustment between the condenser sides.

In the .preferred embodiment `oi" -tbe invention tbe resistance element 'includes a bcdy of insulatingV material 9, suoli as sheet et paper7 this insulating element being.;v clamped between an extension of the dielectrie 3 and e metal clip 10 which is in gripping engagement Witli the extension of tlie dielectric that is tucked in between the Sidee4 of the clip. The clip, as a. Whole,- is ott' U-sliepe ann eaeli Side of it is alSo'U-Shaped in cross section. One terminal ll ot' the resietence ie preferably formed by a broad line of india ink Whose carbon is a suitable conductor. The other terminal l2 ot' the ref 'fan-fe in a similar broad line ot indiaink. rlnese spared apart resistance terminals ll and i2, being very tlin layers et current el, may readily be'jcined Through linee ot c bon i3 made by writing instrument7 preferably a pencil` lead pencil lines i'ezwlily nier with the inl; lines. 'llie resistance al 'il is firmly held in Contact with condenser side l, beingI firmly pressed into engagement with side by reason of tlie facttlieit its mounting 9 is tightly 'received between said condenser side and the dielectric. The resistance terminal 12 is irmly lield in engngement with tlie 'metallic clip 10./ tlie mounting 9 being firmly 'clamped between one fold of tlie clip and the dielectric. The inner opposed faces of the clip and-the cio-ndenser side 4f are in `sliding vrelation so 'that the capacity of the condenser may be varied Without modifying the resistance adjustment. VVllile the resistance element is conducting met@ preferably mechanically assemble-d With the non-sliding side of the condenser, the invention is not to be tlins limited.

'iflie condenser et my invention is of par-- ticnlar service when employed in connection with Wireless systems of communication and tbe resistance element of my invention ie ,ierting' trein tlie Spirit ol'-nfiyinyention, but

i vingtliie de, willed myiinvention l claim new and de ire to `eecinre by Letters Petent the Vfollowing:

-iiin electric condenser :including flattened coiled sheets of dielectric materialzindslieet metal, the lattersurroundingtlie former'and constituting oneside of'thecondenser; and a fiat sheet of metal constituting the remainii'llgg side of the condenser andlocatedwithin the bcre'o'f tliecoiled dielectricand movable longitudinally thereof". to adjust'tlie` capacity of the condenser.

in witness whereof, I lier'euntosubscribe my nametliis 25th day of yMay A. L'D., 1923.

l JOHN F. LINDBERG. 

